webhooker/internal/middleware/middleware_test.go

package middleware_test

import (
	"context"
	"encoding/base64"
	"io"
	"log/slog"
	"net/http"
	"net/http/httptest"
	"os"
	"strings"
	"testing"

	"github.com/gorilla/sessions"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"sneak.berlin/go/webhooker/internal/config"
	"sneak.berlin/go/webhooker/internal/middleware"
	"sneak.berlin/go/webhooker/internal/session"
)

const testKeySize = 32

// testMiddleware creates a Middleware with minimal dependencies
// for testing. It uses a real session.Session backed by an
// in-memory cookie store.
func testMiddleware(
	t *testing.T,
	env string,
) (*middleware.Middleware, *session.Session) {
	t.Helper()

	log := slog.New(slog.NewTextHandler(
		os.Stderr,
		&slog.HandlerOptions{Level: slog.LevelDebug},
	))

	cfg := &config.Config{
		Environment: env,
	}

	// Create a real session manager with a known key
	key := make([]byte, testKeySize)

	for i := range key {
		key[i] = byte(i)
	}

	store := sessions.NewCookieStore(key)
	store.Options = &sessions.Options{
		Path:     "/",
		MaxAge:   86400 * 7,
		HttpOnly: true,
		Secure:   false,
		SameSite: http.SameSiteLaxMode,
	}

	sessManager := session.NewForTest(store, cfg, log, key)

	m := middleware.NewForTest(log, cfg, sessManager)

	return m, sessManager
}

// --- Logging Middleware Tests ---

func TestLogging_SetsStatusCode(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	handler := m.Logging()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			w.WriteHeader(http.StatusCreated)

			_, err := w.Write([]byte("created"))
			if err != nil {
				return
			}
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(), http.MethodGet, "/test", nil)
	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.Equal(t, http.StatusCreated, w.Code)
	assert.Equal(t, "created", w.Body.String())
}

func TestLogging_DefaultStatusOK(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	handler := m.Logging()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			_, err := w.Write([]byte("ok"))
			if err != nil {
				return
			}
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(), http.MethodGet, "/", nil)
	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	// When no explicit WriteHeader is called, default is 200
	assert.Equal(t, http.StatusOK, w.Code)
}

func TestLogging_PassesThroughToNext(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	var called bool

	handler := m.Logging()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			called = true

			w.WriteHeader(http.StatusOK)
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodPost, "/api/webhook", nil,
	)
	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.True(
		t, called,
		"logging middleware should call the next handler",
	)
}

// --- LoggingResponseWriter Tests ---

func TestLoggingResponseWriter_CapturesStatusCode(t *testing.T) {
	t.Parallel()

	w := httptest.NewRecorder()
	lrw := middleware.NewLoggingResponseWriterForTest(w)

	// Default should be 200
	assert.Equal(
		t, http.StatusOK,
		middleware.LoggingResponseWriterStatusCode(lrw),
	)

	// WriteHeader should capture the status code
	lrw.WriteHeader(http.StatusNotFound)

	assert.Equal(
		t, http.StatusNotFound,
		middleware.LoggingResponseWriterStatusCode(lrw),
	)

	// Underlying writer should also get the status code
	assert.Equal(t, http.StatusNotFound, w.Code)
}

func TestLoggingResponseWriter_WriteDelegatesToUnderlying(
	t *testing.T,
) {
	t.Parallel()

	w := httptest.NewRecorder()
	lrw := middleware.NewLoggingResponseWriterForTest(w)

	n, err := lrw.Write([]byte("hello world"))
	require.NoError(t, err)
	assert.Equal(t, 11, n)
	assert.Equal(t, "hello world", w.Body.String())
}

// --- CORS Middleware Tests ---

func TestCORS_DevMode_AllowsAnyOrigin(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	handler := m.CORS()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			w.WriteHeader(http.StatusOK)
		},
	))

	// Preflight request
	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodOptions, "/api/test", nil,
	)
	req.Header.Set("Origin", "http://localhost:3000")
	req.Header.Set("Access-Control-Request-Method", "POST")

	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	// In dev mode, CORS should allow any origin
	assert.Equal(
		t, "*",
		w.Header().Get("Access-Control-Allow-Origin"),
	)
}

func TestCORS_ProdMode_NoOp(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentProd)

	var called bool

	handler := m.CORS()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			called = true

			w.WriteHeader(http.StatusOK)
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/api/test", nil,
	)
	req.Header.Set("Origin", "http://evil.com")

	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.True(
		t, called,
		"prod CORS middleware should pass through to handler",
	)
	// In prod, no CORS headers should be set (no-op middleware)
	assert.Empty(
		t,
		w.Header().Get("Access-Control-Allow-Origin"),
		"prod mode should not set CORS headers",
	)
}

// --- RequireAuth Middleware Tests ---

func TestRequireAuth_NoSession_RedirectsToLogin(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	var called bool

	handler := m.RequireAuth()(http.HandlerFunc(
		func(_ http.ResponseWriter, _ *http.Request) {
			called = true
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/dashboard", nil,
	)
	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.False(
		t, called,
		"handler should not be called for "+
			"unauthenticated request",
	)
	assert.Equal(t, http.StatusSeeOther, w.Code)
	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
}

func TestRequireAuth_AuthenticatedSession_PassesThrough(
	t *testing.T,
) {
	t.Parallel()

	m, sessManager := testMiddleware(t, config.EnvironmentDev)

	var called bool

	handler := m.RequireAuth()(http.HandlerFunc(
		func(_ http.ResponseWriter, _ *http.Request) {
			called = true
		},
	))

	// Create an authenticated session by making a request,
	// setting session data, and saving the session cookie
	setupReq := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/setup", nil,
	)
	setupW := httptest.NewRecorder()

	sess, err := sessManager.Get(setupReq)
	require.NoError(t, err)
	sessManager.SetUser(sess, "user-123", "testuser")
	require.NoError(t, sessManager.Save(setupReq, setupW, sess))

	// Extract the cookie from the setup response
	cookies := setupW.Result().Cookies()
	require.NotEmpty(t, cookies, "session cookie should be set")

	// Make the actual request with the session cookie
	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/dashboard", nil,
	)

	for _, c := range cookies {
		req.AddCookie(c)
	}

	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.True(
		t, called,
		"handler should be called for authenticated request",
	)
}

func TestRequireAuth_UnauthenticatedSession_RedirectsToLogin(
	t *testing.T,
) {
	t.Parallel()

	m, sessManager := testMiddleware(t, config.EnvironmentDev)

	var called bool

	handler := m.RequireAuth()(http.HandlerFunc(
		func(_ http.ResponseWriter, _ *http.Request) {
			called = true
		},
	))

	// Create a session but don't authenticate it
	setupReq := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/setup", nil,
	)
	setupW := httptest.NewRecorder()

	sess, err := sessManager.Get(setupReq)
	require.NoError(t, err)
	// Don't call SetUser -- session exists but is not
	// authenticated
	require.NoError(t, sessManager.Save(setupReq, setupW, sess))

	cookies := setupW.Result().Cookies()
	require.NotEmpty(t, cookies)

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/dashboard", nil,
	)

	for _, c := range cookies {
		req.AddCookie(c)
	}

	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.False(
		t, called,
		"handler should not be called for "+
			"unauthenticated session",
	)
	assert.Equal(t, http.StatusSeeOther, w.Code)
	assert.Equal(t, "/pages/login", w.Header().Get("Location"))
}

// --- NoCache Middleware Tests ---

func TestNoCache_SetsHeaders(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	var called bool

	handler := m.NoCache()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			called = true

			w.WriteHeader(http.StatusOK)
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/sources", nil,
	)
	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.True(
		t, called,
		"NoCache middleware should call the next handler",
	)
	assert.Equal(
		t, "no-store",
		w.Header().Get("Cache-Control"),
	)
	assert.Equal(
		t, "no-cache",
		w.Header().Get("Pragma"),
	)
}

// --- MaxBodySize Middleware Tests ---

const testBodyLimit int64 = 64

// maxBodySizeHandler wraps a sentinel handler in MaxBodySize with
// testBodyLimit. The sentinel records whether it ran and how much of
// the body it managed to read, so tests can distinguish "never
// reached" from "reached but truncated".
type maxBodySizeResult struct {
	called   bool
	read     int
	readErr  error
	response *httptest.ResponseRecorder
}

func runMaxBodySize(
	t *testing.T,
	req *http.Request,
) *maxBodySizeResult {
	t.Helper()

	m, _ := testMiddleware(t, config.EnvironmentDev)
	res := &maxBodySizeResult{response: httptest.NewRecorder()}

	handler := m.MaxBodySize(testBodyLimit)(http.HandlerFunc(
		func(w http.ResponseWriter, r *http.Request) {
			res.called = true

			body, err := io.ReadAll(r.Body)
			res.read = len(body)
			res.readErr = err

			w.WriteHeader(http.StatusOK)
		},
	))

	handler.ServeHTTP(res.response, req)

	return res
}

// postWithBody builds a POST request whose Content-Length is
// accurate for the given payload size.
func postWithBody(size int) *http.Request {
	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodPost, "/pages/login",
		strings.NewReader(strings.Repeat("a", size)),
	)
	req.Header.Set(
		"Content-Type", "application/x-www-form-urlencoded",
	)

	return req
}

func TestMaxBodySize_DeclaredOversize_413AndHandlerNotReached(
	t *testing.T,
) {
	t.Parallel()

	res := runMaxBodySize(t, postWithBody(int(testBodyLimit)+1))

	assert.False(
		t, res.called,
		"handler must not be reached for an oversized body",
	)
	assert.Equal(
		t, http.StatusRequestEntityTooLarge, res.response.Code,
	)
}

func TestMaxBodySize_AtLimit_PassesThrough(t *testing.T) {
	t.Parallel()

	res := runMaxBodySize(t, postWithBody(int(testBodyLimit)))

	assert.True(
		t, res.called,
		"handler should be reached for a body at the limit",
	)
	require.NoError(t, res.readErr)
	assert.Equal(t, int(testBodyLimit), res.read)
	assert.Equal(t, http.StatusOK, res.response.Code)
}

func TestMaxBodySize_UnderLimit_PassesThrough(t *testing.T) {
	t.Parallel()

	res := runMaxBodySize(t, postWithBody(1))

	assert.True(t, res.called)
	require.NoError(t, res.readErr)
	assert.Equal(t, 1, res.read)
	assert.Equal(t, http.StatusOK, res.response.Code)
}

func TestMaxBodySize_GetWithOversizeBody_NotCapped(t *testing.T) {
	t.Parallel()

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/pages/login",
		strings.NewReader(
			strings.Repeat("a", int(testBodyLimit)+1),
		),
	)

	res := runMaxBodySize(t, req)

	assert.True(
		t, res.called,
		"GET requests are not subject to the POST body cap",
	)
	require.NoError(t, res.readErr)
	assert.Equal(t, int(testBodyLimit)+1, res.read)
}

// TestMaxBodySize_UndeclaredOversize_TruncatedAtCap covers the
// chunked / lying-Content-Length case: there is nothing to check up
// front, so the request reaches the handler but MaxBytesReader
// hard-caps the body and the read fails at the limit.
func TestMaxBodySize_UndeclaredOversize_TruncatedAtCap(
	t *testing.T,
) {
	t.Parallel()

	req := postWithBody(int(testBodyLimit) + 1)
	// Simulate a chunked request: no declared length.
	req.ContentLength = -1

	res := runMaxBodySize(t, req)

	assert.True(
		t, res.called,
		"an undeclared oversize body cannot be rejected up front",
	)
	require.Error(
		t, res.readErr,
		"reading past the cap must fail",
	)
	assert.Equal(
		t, int(testBodyLimit), res.read,
		"the handler must not see more than the cap",
	)
}

// --- Helper Tests ---

func TestIpFromHostPort(t *testing.T) {
	t.Parallel()

	tests := []struct {
		name     string
		input    string
		expected string
	}{
		{"ipv4 with port", "192.168.1.1:8080", "192.168.1.1"},
		{"ipv6 with port", "[::1]:8080", "::1"},
		{"invalid format", "not-a-host-port", ""},
		{"empty string", "", ""},
		{"localhost", "127.0.0.1:80", "127.0.0.1"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			t.Parallel()

			result := middleware.IPFromHostPort(tt.input)

			assert.Equal(t, tt.expected, result)
		})
	}
}

// --- MetricsAuth Tests ---

// metricsAuthMiddleware creates a Middleware configured for
// metrics auth testing. This helper de-duplicates the setup in
// metrics auth test functions.
func metricsAuthMiddleware(
	t *testing.T,
) *middleware.Middleware {
	t.Helper()

	log := slog.New(slog.NewTextHandler(
		os.Stderr,
		&slog.HandlerOptions{Level: slog.LevelDebug},
	))

	cfg := &config.Config{
		Environment:     config.EnvironmentDev,
		MetricsUsername: "admin",
		MetricsPassword: "secret",
	}

	key := make([]byte, testKeySize)
	store := sessions.NewCookieStore(key)
	store.Options = &sessions.Options{Path: "/", MaxAge: 86400}

	sessManager := session.NewForTest(store, cfg, log, key)

	return middleware.NewForTest(log, cfg, sessManager)
}

// runMetricsAuthRequest sends a GET /metrics request with the
// given basic-auth password through MetricsAuth and reports
// whether the wrapped handler ran plus the recorded response.
func runMetricsAuthRequest(
	t *testing.T, password string,
) (bool, *httptest.ResponseRecorder) {
	t.Helper()

	m := metricsAuthMiddleware(t)

	var called bool

	handler := m.MetricsAuth()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			called = true

			w.WriteHeader(http.StatusOK)
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/metrics", nil,
	)
	req.SetBasicAuth("admin", password)

	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	return called, w
}

func TestMetricsAuth_ValidCredentials(t *testing.T) {
	t.Parallel()

	called, w := runMetricsAuthRequest(t, "secret")

	assert.True(
		t, called,
		"handler should be called with valid basic auth",
	)
	assert.Equal(t, http.StatusOK, w.Code)
}

func TestMetricsAuth_InvalidCredentials(t *testing.T) {
	t.Parallel()

	called, w := runMetricsAuthRequest(t, "wrong-password")

	assert.False(
		t, called,
		"handler should not be called with invalid basic auth",
	)
	assert.Equal(t, http.StatusUnauthorized, w.Code)
}

func TestMetricsAuth_NoCredentials(t *testing.T) {
	t.Parallel()

	m := metricsAuthMiddleware(t)

	var called bool

	handler := m.MetricsAuth()(http.HandlerFunc(
		func(_ http.ResponseWriter, _ *http.Request) {
			called = true
		},
	))

	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodGet, "/metrics", nil,
	)
	// No basic auth header
	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	assert.False(
		t, called,
		"handler should not be called without credentials",
	)
	assert.Equal(t, http.StatusUnauthorized, w.Code)
}

// --- CORS Dev Mode Detailed Tests ---

func TestCORS_DevMode_AllowsMethods(t *testing.T) {
	t.Parallel()

	m, _ := testMiddleware(t, config.EnvironmentDev)

	handler := m.CORS()(http.HandlerFunc(
		func(w http.ResponseWriter, _ *http.Request) {
			w.WriteHeader(http.StatusOK)
		},
	))

	// Preflight for POST
	req := httptest.NewRequestWithContext(
		context.Background(),
		http.MethodOptions, "/api/webhooks", nil,
	)
	req.Header.Set("Origin", "http://localhost:5173")
	req.Header.Set("Access-Control-Request-Method", "POST")

	w := httptest.NewRecorder()

	handler.ServeHTTP(w, req)

	allowMethods := w.Header().Get("Access-Control-Allow-Methods")
	assert.Contains(t, allowMethods, "POST")
}

// --- Base64 key validation for completeness ---

func TestSessionKeyFormat(t *testing.T) {
	t.Parallel()

	// Verify that the session initialization correctly validates
	// key format. A proper 32-byte key encoded as base64 should
	// work.
	key := make([]byte, testKeySize)

	for i := range key {
		key[i] = byte(i + 1)
	}

	encoded := base64.StdEncoding.EncodeToString(key)
	decoded, err := base64.StdEncoding.DecodeString(encoded)
	require.NoError(t, err)
	assert.Len(t, decoded, testKeySize)
}